Field is a linked piece of text that shows the property of the object it is linked to. Properties of Field text are determined by the text style, and for that reason, we will modify the text style in our drawing before we start learning about fields.

In the following example, I will make a text style called Field Style and then I will use this text style for all the fields:

1. Select the text style icon from the expanded Annotation panel of the Home tab or use its command alias, ST.
2. Click the New button on the Text Style window and give the text style a name. For this example, name it Field Style, and then click OK.
3. Now, change the font to simplex.shx and the font height to 2.5000.
4. Click Apply and then Close to apply these changes, and then close the Text Style window. My final text style settings for Field Style appeared as shown in Figure 7.36:

Now that we have our text style, we are ready to add our fields to our drawing, and the fields will now use the current text style, Field Style, which we created just now.

In the next example, we will create a field that represents the area of a closed polyline shape:

1. Make a closed polyline shape with lines and arcs as shown in Figure 7.37. In my drawing, the length of the horizontal line at the bottom of this polyline shape is 50 units, and the dimensions of other lines and arcs are randomly selected:

2. Type FIELD in the command line and press the Enter key; the Field window will open.
3. In the Field category dropdown, select the Objects option and the Field names panel will update with a different set of options.
4. Select Object from the Field names panel and then click the box near the Object type option that looks like an AutoCAD pointer.
5. Now, the Field window will be hidden and you will see a selection box. Click the polyline and the Field window will show up again.
6. Now, the Property panel underneath the Object type option will populate with a list of properties associated with our selected polyline. Select Area from the list of properties and then select Decimal from the Format panel.

7. Click OK when you are done making these changes in the Field window. The workflow of creating fields is also shown in Figure 7.38:

8. Now the area of the polyline will show up on your cursor. Click inside the polyline to place the field and you now have an area field that is linked to the polyline.
9. Change the area of the polyline by moving the lines or arcs using grips and then type RE and press Enter to regenerate the drawing; you will notice that the area shown in the field will also update.

The hallmark of a field is a gray background, and you will see this for the area field too. This gray background of the field is only visible in the drawing area and will not show up when you plot your drawing. The fields of a drawing will be plotted as simple text without any gray background. In my example, the field with the area looked like Figure 7.39:

So, this was just one example where fields can be used. There are many other object types for which you can add fields; for instance, you could add a field for viewport scale, which we discussed in our chapter on printing and plotting, or a field for data and time.

Now, we will move on to another topic that is completely different from fields: custom linetypes and hatches. In the next section, we will learn to make custom linetypes using linetype code and custom hatches using express tools.